<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<ul>
    <li data-exercise-id="1">1</li>
    <li>2</li>
    <li>3</li>
    <li>4</li>
    <li>5</li>
</ul>
<script src="./js/jquery.js"></script>
<script>
    $(function () {
        var li = $("li[data-exercise-id='"+1+"']");
        console.log(li);
//        window.baozitang.toast(li);
            });
</script>
</body>
</html>